1. Field of the Invention
The invention is drawn to a group of compounds with specific structure, which possess anti-cancer activity. It also relates to processes of making these compounds, and processes for their use in human and other mammalian subjects for cancer therapy, prevention, and immune boosting functions.
2. Description of the Background
Extensive studies have been underway for over 2 decades to identify drugs that could be used to treat cancer. Drugs that either directly or indirectly cause tumor cell growth arrest, or cause tumor cell death via apoptotic mechanisms have been identified. However, major limiting factors in anticancer therapy still exist, i.e. drugs' adverse effects on normal cells and drug resistance developed by cancer cells. Some new approaches, such as anti-angiogenesis approach, represent new avenues of fighting cancer.
Nonetheless the most direct approach to stop cancer is to use drugs that kill tumor cells. As mentioned above, one major drawback of these conventional cancer-killing drugs is that they also kill non-cancerous cells and cause severe adverse effects. In an effort to search for anti-cancer agents that have minimal effects on normal tissue, a group of compounds with specific structure that directly kill cancer cells but do not harm normal cells have recently been identified.
A group of specific iso- and anteiso-branched-chain fatty acids with significant anti-cancer effect has been described in Applicant's U.S. application Ser. No. 09/173,681, now U.S. Pat. No. 6,214,875. Such compounds as described in the above Applicant's U.S. Application, and derivatives thereof obtained by reacting the acid moiety thereof, are described in Applicant's WO 99/53086. These compounds have shown excellent cytotoxic activity through induction of apoptosis against a broad variety of cancer cells, including, but not limited to, leukemia, breast cancer, prostate cancer, lung cancer, with extremely low toxicity to experimental animals.
JP-A 04295423 and JP-B 07072134, each to Daiichi, disclose anti-cancer agents containing MeCHR(CH2)nCOOH wherein R is C1–C5 alkyl and n=4–22. U.S. Pat. No. 4,985,466 to Deguchi disclose a method for treating tumors susceptible to treatment with a wool fatty acid, or its reduced alcohol, metal salt or aliphatic ester derivative, or a wool alcohol, or its carboxylic acid, aliphatic ether or aliphatic ester derivative. Deguchi additionally disclose that it is characteristic of wool fatty acid and wool alcohol to contain a large quantity of iso- and anteiso- higher saturated aliphatic compounds. Deguchi also exemplifies a number of specific iso- and anteiso-higher saturated aliphatic acids and alcohols.
However, none of the above prior art recognizes Applicant's discovery that the anti-cancer activity resides in a terminal branch structure and a polar group per se directly linked at opposite ends, respectively, of a long chain group.